CN117117493B

CN117117493B - Antenna device

Info

Publication number: CN117117493B
Application number: CN202311382718.7A
Authority: CN
Inventors: 闻娟; 曾玲玲
Original assignee: Continental Automotive Parts Suzhou Co Ltd
Current assignee: Continental Automotive Parts Suzhou Co Ltd
Priority date: 2023-10-24
Filing date: 2023-10-24
Publication date: 2024-02-06
Anticipated expiration: 2043-10-24
Also published as: CN117117493A

Abstract

The invention relates to an antenna device, which comprises an upper dielectric plate and a lower dielectric plate which are stacked up and down and are arranged at intervals, wherein a grounding layer is arranged on the lower dielectric plate, the antenna device comprises a frequency band control unit, the frequency band control unit comprises a first feeder line, a second feeder line and a radiation loop which is arranged on the lower dielectric plate and has a rotationally symmetrical geometric shape, the first feeder line and the second feeder line are respectively connected to a first feed point and a second feed point of a radiation loop by virtue of a first feed structure and a second feed structure so as to realize the feed of the radiation loop, the connecting line of the first feed point and the center of the radiation loop is perpendicular to the connecting line of the second feed point and the center of the radiation loop, the frequency band control unit also comprises a plurality of groups of parasitic branches which are arranged on the upper dielectric plate, each group of parasitic branches is respectively in short connection with the grounding layer, and the plurality of groups of parasitic branches are arranged so that the radiation loop and the parasitic branches are combined to form a tightly coupled electric field.

Description

Antenna device

Technical Field

The present invention relates to the field of satellite communication equipment, and in particular to an antenna arrangement for satellite positioning.

Background

At present, most of vehicle-mounted circularly polarized antennas covering high-precision GNSS (Global Navigation Satellite System) satellite positioning are double-frequency-band ceramic patch antennas, and the antennas are formed by stacking and combining two thicker ceramic blocks up and down, and the height difference exists between the equivalent phase centers of two frequency points in the vertical direction, so that the requirement of consistency of the double-frequency phase centers of a high-precision satellite positioning system is not met. And the surfaces of the upper ceramic block and the lower ceramic block are plated with a plurality of metal coating layers, and the metal coating layers are mutually coupled, so that two working frequency points are mutually influenced, and independent debugging is not easy to realize.

In addition, the design process of the existing vehicle-mounted antenna (such as a double-frequency double-fed circularly polarized satellite antenna) also encounters the following technical problems: the height direction of the dual-frequency phase center of the satellite positioning system is inconsistent; the radiation field of the antenna is easily interfered by the external environment, so that the transmission performance of the antenna is reduced; for a dual-frequency antenna, unnecessary coupling can be generated between the radiation structures of the two frequency bands, the radiation fields of the two frequency bands are mutually influenced, and the independent design of the structures of each frequency band is not easy; the antenna section is higher, which is not beneficial to assembly; the isolation degree of the multi-frequency antenna integration is insufficient, and the signal crosstalk is strong; the antenna development and manufacturing costs are high, etc.

The present invention is directed to overcoming one or more of the problems of the existing antennas.

Disclosure of Invention

The antenna device according to the present invention enables to provide a high-precision GNSS satellite positioning, vehicle-mounted circularly polarized antenna, which is optimized in performance and structure, and to provide an antenna comprising a single band or a dual band (e.g., GNSS L1 (1.559-1.606 GHz), GNSS L5 (1.166-1.192 GHz)) or more, having low profile, compactness and excellent positioning performance.

In view of this, according to an aspect of the present invention, there is provided an antenna device characterized by comprising an upper dielectric plate and a lower dielectric plate stacked one above the other, arranged at intervals, on which a ground layer is provided, the antenna device comprising a frequency band control unit including a first feeder line and a second feeder line provided on the lower dielectric plate and a radiation loop provided on the upper dielectric plate and having a rotationally symmetrical geometry, the first feeder line and the second feeder line being coupled to a first feed point and a second feed point of the radiation loop by means of a first feed structure and a second feed structure, respectively, so as to realize feeding of the radiation loop, a connecting line of the first feed point and a center of the radiation loop being perpendicular to a connecting line of the second feed point and a center of the radiation loop, the frequency band control unit further including a plurality of sets of parasitic branches provided on the upper dielectric plate, each set of parasitic branches being shorted to the ground layer, respectively, the plurality of sets of parasitic branches forming a close-spaced combination of parasitic radiation and parasitic radiation adjacent to each other along the loop around the vertical axis of the radiation loop.

The antenna device has a planar loop antenna structure and adopts a GNSS single-frequency double-fed circularly polarized antenna structure. The radiation loop adopts independent orthogonal direction coupling feed ports, and the unique electric field zero pole distribution characteristic improves the isolation between two orthogonal feed ports in the same frequency band. In addition, by forming a tightly coupled electric field between the radiating loop and the parasitic stub, the antenna device can be made to form an inwardly coupled confining field, reducing interference from the external environment. In addition, based on the antenna structure, the antenna device with high precision and double/more frequencies can be expanded according to different satellite positioning frequency band requirements.

Advantageously, the geometry of the radiating loop is square and the first and second feed points of the radiating loop are respectively arranged at the centre points of two adjacent sides of the radiating loop.

Advantageously, the plurality of sets of parasitic branches comprises four sets of parasitic branches respectively disposed on the parasitic loop adjacent to four corners of the radiating loop, each set of parasitic branches comprising branch legs extending parallel to adjacent sides of the radiating loop.

Advantageously, the plurality of sets of parasitic branches are located on the same plane as the radiating loop.

Advantageously, the parasitic ring is arranged inside the radiation loop.

Advantageously, the frequency band control unit further comprises a deployment stub provided on the upper dielectric plate for adjusting the antenna performance, the deployment stub extending from the radiating loop towards the center of the radiating loop.

Advantageously, the antenna device comprises two frequency band control units, wherein the radiation loop of the first frequency band control unit and the radiation loop of the second frequency band control unit are concentric and are arranged on the upper dielectric plate in a coplanar manner, the radiation loop of the first frequency band control unit and the radiation loop of the second frequency band control unit are similar in shape, the symmetry axes are coincident, and the two are separated by a preset distance.

Advantageously, the applicable frequency of the first frequency band control unit is higher than the applicable frequency of the second frequency band control unit, the imaginary parasitic loop of the first frequency band control unit is arranged on the same plane as the radiating loop of the first frequency band control unit and is located inside the radiating loop of the first frequency band control unit, and the imaginary parasitic loop of the second frequency band control unit is arranged on the same plane as the radiating loop of the second frequency band control unit and is located outside the radiating loop of the second frequency band control unit.

Advantageously, the radiating loops of the first frequency band control unit and the radiating loops of the second frequency band control unit are square, the two radiating loops have two common diagonals, the first feed point and the second feed point of the radiating loops of the first frequency band control unit are symmetrically arranged at the center points of two adjacent sides of the radiating loops of the first frequency band control unit about the first diagonal, the first feed point and the second feed point of the radiating loops of the second frequency band control unit are symmetrically arranged at the center points of two adjacent sides of the radiating loops of the second frequency band control unit about the first diagonal, and the first feed point and the second feed point of the radiating loops of the first frequency band control unit and the first feed point and the second feed point of the radiating loops of the second frequency band control unit are located on different sides of the second diagonal of the two common diagonals.

Advantageously, the parasitic branches of the second band control element comprise four sets of second parasitic branches respectively arranged on parasitic loops located outside the radiating loop of the second band control element, adjacent to the four corners of the radiating loop of the second band control element, each set of second parasitic branches comprising branch legs extending parallel to the adjacent two sides of the radiating loop.

Advantageously, the first frequency band control unit comprises a first deployment branch arranged on said upper dielectric plate extending from the radiating loop of the first frequency band control unit towards the centre of the radiating loop of the first frequency band control unit, at least one pair of symmetrically arranged on said diagonal, and/or the second frequency band control unit comprises a second deployment branch arranged on said upper dielectric plate extending from the radiating loop of the second frequency band control unit towards the centre of the radiating loop of the second frequency band control unit, at least one pair of symmetrically arranged on said diagonal.

The dual-band antenna device according to the present invention has a low profile structural characteristic (e.g., 0.05λ ₀ The overall side height) of the vehicle body can be flexibly integrated into the plane design of the vehicle body to form the vehicle-mounted hidden satellite positioning antenna system. In satellite positioning antenna systems and other high-precision positioning applications, dual-band antennas are often used to receive and process signals at different frequencies to achieve higher positioning accuracy. Because different phase delays can appear in the signals of different frequency bands in the propagation process, the same phase center position of the antenna on the two frequency bands is required to be ensured, so that the signals of the two frequency bands can be correctly combined and processed, and the positioning accuracy is improved. According to the design structure of the dual-frequency antenna device, the centers of the two radiation loops corresponding to two different GNSS working frequency points are coincident, so that the relatively ideal dual-frequency equivalent phase center consistency is met, and the performance of a high-precision satellite positioning system is improved. In addition, the double-frequency antenna device provided by the invention has an inward coupling constraint field, reduces the coupling with other frequency point radiation loops, and is easy for double-frequency independent design.

Advantageously, the antenna device comprises three or more frequency band control units, the radiation loops of the frequency band control units are arranged on the upper dielectric plate in a coplanar and concentric manner, two adjacent radiation loops are separated by a preset distance, the radiation loops of all the frequency band control units are similar in shape, and the symmetry axes are coincident.

Advantageously, the upper dielectric plate is supported on the lower dielectric plate by means of at least one support structure.

Advantageously, the at least one support structure comprises a metal post for connecting a parasitic stub of the frequency band control unit with a ground plane of the underlying dielectric plate.

Advantageously, a hollowed-out structure is formed at the center of the upper dielectric plate.

Advantageously, the upper dielectric plate and the lower dielectric plate are PCB boards/printed circuit boards.

The antenna device according to the invention can be used as a hidden vehicle-mounted circularly polarized antenna for high-precision GNSS satellite positioning. The circularly polarized antenna can be used for receiving and transmitting various types of circularly polarized signals, such as GPS signals, mobile communication signals, satellite television signals, radio signals, etc. The circularly polarized signal has better transmission performance than the linearly polarized signal, and can effectively reduce signal attenuation and multipath interference, so that the circularly polarized signal is widely applied to vehicles such as vehicles. Furthermore, the circularly polarized antenna arrangement according to the invention is integrated with single-frequency or double-frequency or multi-frequency operating bands for GNSS vehicle satellite positioning. The circularly polarized antenna device has the characteristic of low-profile structure, can be flexibly integrated into the plane design of a vehicle body, has ideal equivalent phase center consistency, and improves the performance of a high-precision satellite positioning system. In addition, the manufacturing process based on the PCB is simple, the manufacturing cost is low, and the mass production is facilitated.

Drawings

Other features and advantages of the methods of the present invention will be apparent from, or are apparent from, the accompanying drawings, which are incorporated herein, and the detailed description of the invention, which, together with the drawings, serve to explain certain principles of the invention.

Fig. 1 shows a schematic perspective view of an antenna device according to a first embodiment of the present invention;

fig. 2 shows a side cross-sectional view of an antenna arrangement according to a first embodiment of the invention;

fig. 3 shows a schematic diagram of an electric field excited by one feed port in an antenna device according to a first embodiment of the present invention;

fig. 4 shows a modification of the arrangement of the first feed point and the second feed point in the antenna device according to the first embodiment of the invention;

fig. 5 shows a modification of the feed line arrangement in the antenna device according to the first embodiment of the present invention;

fig. 6 shows an S-parameter graph of an antenna arrangement according to a first embodiment of the invention;

fig. 7 shows an axial ratio diagram of an antenna device according to a first embodiment of the present invention;

fig. 8 shows a radiation gain diagram of an antenna arrangement according to a first embodiment of the invention;

fig. 9 shows a schematic perspective view of an antenna arrangement according to a second embodiment of the invention;

fig. 10 shows a schematic plan view of an antenna arrangement according to a second embodiment of the invention;

Fig. 11 shows an S-parameter graph of an antenna arrangement according to a second embodiment of the invention.

Detailed Description

An antenna device according to the present invention will be described below by way of embodiments with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention to those skilled in the art. It will be apparent, however, to one skilled in the art that the present invention may be practiced without some of these specific details. Rather, the invention can be considered to be implemented with any combination of the following features and elements, whether or not they relate to different embodiments. Thus, the various aspects, features, embodiments and advantages described below are for illustration only and should not be considered elements or limitations of the claims.

The antenna device generally has a planar loop antenna structure, is realized based on a dielectric plate such as a PCB, has lower overall side height, can be flexibly integrated into a vehicle body planar design, and forms a vehicle-mounted hidden satellite positioning antenna system.

First embodiment of antenna device

Fig. 1-2 show an antenna arrangement 1' according to a first embodiment of the invention. The antenna device 1' includes an upper dielectric plate 11 and a lower dielectric plate 12 stacked one above the other and arranged at intervals. The upper dielectric plate is supported on the lower dielectric plate, for example by means of a support structure. In the advantageous embodiment shown in fig. 1, both the upper dielectric plate 11 and the lower dielectric plate 12 are implemented as PCB boards. Advantageously, the upper dielectric plate is parallel to the lower dielectric plate.

The antenna device 1 'according to the present embodiment includes a band control unit 10' configured to control the performance of a specific band of the antenna device. The band control unit 10 'includes a first power supply line 101' and a second power supply line 102 'provided on the lower dielectric plate 12, and a radiation loop 103' having a rotationally symmetrical geometry provided on the upper dielectric plate 11. The radiation loops 103' are etched on planar sides (e.g., bottom side planes) of the upper dielectric plate 11. The first feeder line 101' and the second feeder line 102' are coupled to the radiating loop 103' by a first feeding structure 1011' and a second feeding structure 1021', respectively, to feed the radiating loop. In the embodiment shown, the first and second feed structures 1011', 1021' are spaced apart from the radiating loop 103 'to provide a coupling feed for the radiating loop 103'. The first feeding structure 1011 'includes a coupling metal post M1 connected to the first feeding line 101' and a patch P1 located above the coupling metal post M1 and spaced apart from the radiation loop 103 'in the vertical direction, and the second feeding structure 1021' includes a coupling metal post M2 connected to the second feeding line 102 'and a patch P2 located above the coupling metal post M2 and spaced apart from the radiation loop 103' in the vertical direction. The patch preferably has a circular shape. The projection positions of the patches of the first and second feeding structures on the radiating loop in the vertical direction can be regarded as a first feed point F1 and a second feed point F2 of the radiating loop.

In the embodiment shown in fig. 1, the connection between the first feed point F1 of the radiation loop 103 'and the center O of the radiation loop 103' is perpendicular to the connection between the second feed point F2 and the center O of the radiation loop, so that one of the feed points feeds a signal at the zero position of the electric field excited on the radiation loop by the other feed point.

The bottom surface of the lower dielectric plate 12 is covered with an entire metal layer (e.g., metal copper) to be implemented as a ground layer 12b, i.e., to serve as a ground for the first and second power supply lines and the radiation loop. Although the ground layer 12b is shown at the bottom of the underlying dielectric plate, it will be appreciated that the ground layer may be provided as other layers of the underlying dielectric plate. For example, the ground layer 12b may be disposed on an upper layer of the lower dielectric plate, and accordingly, the first and second power supply lines may be disposed on a lower layer of the lower dielectric plate.

The band control unit 10 'further includes a plurality of sets of parasitic branches 104' p disposed on an upper dielectric plate. Each set of parasitic branches is shorted to the ground layer 12b, respectively, and the sets of parasitic branches are distributed at intervals from each other on an imaginary parasitic ring C extending along and adjacent to the radiating loop around a vertical axis passing through the center of the radiating loop, such that the radiating loop and the parasitic branches combine to form a tightly coupled electric field. In the embodiment shown in fig. 1, the multiple sets of parasitic branches 104'p are disposed on the same plane as the radiating loops 103' on the upper dielectric plate. In an advantageous embodiment, the parasitic loop C in which the parasitic stub is located is arranged inside the radiation loop 103'.

In the illustrated embodiment, the radiation loop 103' is generally square. The first feed point and the second feed point of the radiation loop are positioned at the center points of two adjacent sides of the square radiation loop. A set of parasitic stubs 104' p are each placed over the parasitic loop adjacent four corners of the square radiating loop. Each set of parasitic branches includes branch legs 104'p1, 104' p2 extending parallel to adjacent sides of the radiating loop. The junction of the two stub legs (i.e., the right angle corner) is shorted to the ground plane 12b of the underlying dielectric plate 12 by the parasitic metal pillar 104' c.

These shorted parasitic branches 104' p arranged on the parasitic loop are typically used to improve the performance of the antenna radiation, such as adjusting impedance matching or controlling the polarization direction of the antenna radiation, etc. In the configuration shown in fig. 1, the parasitic dendrites 104'p form a tightly coupled electric field with the square radiating loop 103', so that the fringe field of the square radiating loop is bound inward by the influence of the short-circuited grounded parasitic dendrites, reducing the outward diffusion of the fringe field, and thus reducing the interference of the external environment with the square radiating loop.

In the embodiment shown in fig. 1, a hollowed-out structure 13 is formed at the center of the upper dielectric plate 11. The hollow structure may be formed by, for example, cutting a portion from the center of the upper dielectric plate.

In the whole, the square radiation loop is combined with the parasitic branches at the four corners of the parasitic loop on the upper dielectric plate 11 to form a horizontal rotation symmetrical structure taking the central normal direction (perpendicular to the upper dielectric plate) of the upper dielectric plate as an axis, so that the first feed point F1 and the second feed point F2 orthogonal to the first feed point in the 90 DEG direction generate equal-amplitude orthogonal linear polarization components, and a circular polarization radiation beam is formed in space.

In particular, as shown in fig. 3, the antenna device 1' may produce an electric field pole-zero distribution in the form of a microstrip patch antenna. In the case of the first feed line 101' and the first feed structure 1011' acting together, the combination of the square radiating loop 103' and the copper-clad surfaces of the coupling short-circuited parasitic branches at the four corners on the parasitic loop C forms an electric field distribution pattern in which the electric field at both sides is strongest and the electric field at the center is weakest. In addition, in the electric field working mode, the weakest part of the electric field is just at the feeding position of the second feeder line 102 'and the second feeding structure 1021', and meanwhile, the coupling metal column carries out coupling feeding on the square radiating loop through the circular patch above, so that the high isolation degree of the double-fed port is formed. Under the double-feed structure, two orthogonal linear polarization radiation components can be excited in far-field space, and further the feed phase shift is combined to form circular polarization radiation.

Although the first feed point F1 and the second feed point F2 are shown in fig. 1 as being located at the center points of two adjacent sides of the square radiation loop, it is understood that the first feed point F1 and the second feed point F2 may be located at non-center point positions of two adjacent sides of the square radiation loop, so long as the connection line of the centers of the first feed point F1 and the radiation loop is perpendicular to the connection line of the centers of the second feed point F2 and the radiation loop, as shown in fig. 4, for example.

In particular, as shown in fig. 5, the upper surface of the lower dielectric plate 12 is etched with a split 90 ° phase shifter circuit, and the first feeder line and the second feeder line are implemented as two transmission lines L1, L2 of different lengths connected to the phase shifter, and the transmission lines L1, L2 are fed with energy through a single port 105.

Referring to fig. 6 to 8, it can be seen that the single-frequency circular polarization performance of the antenna device 1' according to the present embodiment is improved. As shown in FIG. 6, a-10 dB impedance bandwidth may achieve a 50MHz operating bandwidth from 1.56GHz to 1.61 GHz. As shown in fig. 7, the 3dB axial ratio bandwidth may meet the operating requirement of the GNSS L1 band. As shown in fig. 8, the maximum circular polarization radiation gain reaches 3dBiC, so that the quality of the transmission signal of the satellite positioning system can be improved.

Referring to fig. 1, the frequency band control unit 10 'further includes a tuning stub 106' provided on the upper dielectric plate for adjusting the antenna performance, the tuning stub extending from the radiation loop toward the center of the radiation loop. In the embodiment shown in fig. 1, the deployment branch 106 'is a pair of branches disposed on a diagonal of the square radiation loop, where the first feed point F1 and the second feed point F2 are respectively located at two sides of the diagonal where the deployment branch 106' is located. By adjusting the length of the deployment stub, the antenna performance may be fine tuned or optimized.

Although shown in fig. 1, in the antenna device 1 'according to the first embodiment of the present invention, the parasitic loop C is located inside the radiation loop 103', it is understood that the parasitic loop (i.e., the parasitic stub) may be disposed outside the radiation loop.

Although in the embodiment shown in fig. 1 the radiating loops are fed by coupling at the first and second feed points, it will be appreciated that the radiating loops may also be fed directly, for example by electrically connecting the upper ends of the coupling metal posts to the radiating loops by soldering.

A second embodiment of an antenna device according to the invention

Based on the first embodiment with a single-frequency loop antenna architecture described above, a second embodiment with a dual-frequency design can be further developed.

Referring to fig. 9 and 10, an antenna device 1 'according to a second embodiment of the present invention includes two band control units, wherein a first band control unit 10 "-1 and a second band control unit 10" -2 have the same configuration as the band control unit 10' of the first embodiment of the present invention.

That is, the first band control unit 10 "-1 has a radiation loop 103" -1, a first feeder line 101 "-1 and a second feeder line 102" -1 for feeding coupling the respective radiation loops, and a parasitic stub 104 "p-1 configured to form a tightly coupled electric field with the respective radiation loops. The first feed line 101'' -1 of the first band control unit 10'' -1 feeds the radiating loop 103'' -1 by coupling through the coupling metal post M1-1 at the first feed point F1-1. The second feeder 102'' -1 of the first band control unit 10'' -1 feeds the radiating loop 103'' -1 by coupling through the coupling metal post M2-1 at the second feed point F2-1.

The second band control unit 10'' -2 has a radiating loop 103'' -2, a first feeder line 101'' -2 and a second feeder line 102'' -2 for feeding coupling the respective radiating loops, and a parasitic branch 104'' -2 configured for forming a tightly coupled electric field with the respective radiating loops. The first feed line 101'' -2 of the second band control unit 10'' -2 feeds the radiating loop 103'' -2 by coupling through the coupling metal post M1-2 at the first feed point F1-2. The second feeder 102'' -2 of the second band control unit 10'' -2 feeds the radiating loop 103'' -2 by coupling through a coupling metal post M2-2 at a second feed point F2-2.

The radiation loop 103 '-1 of the first frequency band control unit 10' -1 and the radiation loop 103 '-2 of the second frequency band control unit 10' -2 are concentrically and coplanar arranged on the upper dielectric plate 11, and the radiation loop of the first frequency band control unit and the radiation loop of the second frequency band control unit are similar in shape, coincide in symmetry axis, and are separated by a predetermined distance.

In the dual band loop antenna embodiment shown in fig. 9 and 10, the first band control unit 10 "-1 with the radiating loop 103" -1 on the inside is a high band control unit. The second band control unit 10 "-2 with the radiation loop 103" -2 at the periphery is a low band control unit. That is, the applicable frequency of the first band control unit is higher than the applicable frequency of the second band control unit. The radiating loop 103 "-1 of the high band control unit and the radiating loop 103" -2 of the low band control unit are square. The imaginary parasitic ring C-1 where the parasitic branch of the high-frequency band control unit is located and the imaginary parasitic ring C-2 where the parasitic branch of the low-frequency band control unit is located are also correspondingly designed to be square.

In the embodiment shown in fig. 9 and 10, the imaginary parasitic loop C-1 (or the corresponding parasitic branch) of the high-band control unit is arranged on the same plane as the radiating loop 103 "-1 of the high-band control unit. The imaginary parasitic loop C-2 (or corresponding parasitic branches) of the low-band control unit is arranged on the same plane as the radiating loop 103 "-2 of the low-band control unit. The parasitic loop C-1 of the high-band control unit is arranged inside the radiating loop 103 "-1 of the high-band control unit. The parasitic loop C-2 of the low band control unit is arranged outside the radiating loop 103 "-2 of the low band control unit. The square radiating loops 103 "-1, 103" -2 are combined together with sets of parasitic branches 104 "p-1, 104" p-2 of the respective frequency bands placed at four right angles on adjacent square parasitic loops to form respective frequency band control portions. Each set of parasitic branches 104 "p-1 of the high-band control unit comprises branch legs 104" p1-1, 104 "p 2-1 extending parallel to adjacent sides of the respective radiating loop 103" 1. Each set of parasitic branches 104 "p-2 of the low-band control unit comprises branch legs 104" p1-2, 104 "p 2-2 extending parallel to adjacent sides of the radiating loop 103" 2.

The two radiation loops 103 "-1, 103" -2 have two common diagonals k1, k2, the first feed point F1-1 and the second feed point F2-1 of the radiation loop of the high-band control unit are symmetrically disposed at the center points of two adjacent sides of the radiation loop 103 "-1 of the high-band control unit with respect to the first diagonal k1, respectively, the first feed point F1-2 and the second feed point F2-2 of the radiation loop of the low-band control unit are symmetrically disposed at the center points of two adjacent sides of the radiation loop 103" -2 of the low-band control unit with respect to the first diagonal k1, respectively, the first feed point F1-1 and the second feed point F2-1 of the radiation loop 103 "-1 of the high-band control unit are located at different sides of the second diagonal k2 of the two common diagonals.

In the low-frequency band control unit, each group of low-frequency parasitic branches 104'' p-2 is shorted to the ground layer 12b of the lower dielectric plate 12 at the connection points (turning right angles) of the branch legs 104'' p1-2, 104'' p2-2 thereof through parasitic metal posts 104'' c-2, and the peripheral square radiation loop 103'' 2 is combined with the groups of low-frequency parasitic branches 104'' p-2 placed at four right angles on the adjacent square parasitic loop together to form a tightly coupled electric field, which constrains the fringe fields of the peripheral square radiation loop.

In the high-frequency band control unit, each set of high-frequency parasitic branches 104 "p-1 is shorted to the ground layer 12b of the lower dielectric plate 12 at the connection points (right angles of turning) of the branch legs 104" p1-1, 104 "p 2-1 thereof through parasitic metal posts 104" c-1, and the inner square radiation loop 103 "1 is combined with the plurality of sets of high-frequency parasitic branches 104" p-1 placed at four right angles on the adjacent square parasitic loop together to form a tightly coupled electric field, which constrains the fringe fields of the inner square radiation loop.

That is, without affecting the design of the square radiation loop 103 "-1 of the high-frequency band control unit (e.g., satellite positioning frequency band of GNSS L1 (1.559-1.606 GHz)), the low-frequency band control unit (e.g., satellite positioning frequency band of GNSS L5 (1.166-1.192 GHz)) is added on the same pair of dielectric plates by disposing the square radiation loop 103" -2 having a larger size and the corresponding short-circuit parasitic branch 104 "p-2 on the periphery of the square radiation loop 103" -1 on the upper dielectric plate 11. The radiation loops of the two-frequency-band control unit have no distance difference in the height direction, so that the consistency of the phase centers of high-precision satellite positioning is ensured.

In addition, the tightly coupled short-circuit parasitic stubs 104 'p-1, 104' p-2 disposed adjacent to the radiating loops 103 '1, 103' 2 of the two band control units ensure in-fringe fields of the radiating loops of the two band control units, thereby not only reducing coupling between the radiating loops of the two band control units, being beneficial to dual band independent design, but also restricting out-coupling and reducing the influence of external environment. Meanwhile, the radiation loops of the two frequency band control units have electric field working modes shown in the figure 3 at the working frequency points, similar zero-pole electric field distribution modes can be formed on the two frequency bands, double-feed ports in the double frequency bands are isolated naturally, and double-frequency double-feed coupling is reduced. The dual-ring structure has symmetrical characteristic, ensures that two orthogonal polarization components with equal amplitude are generated through orthogonal ports under two frequency bands, and is convenient for generating dual-band circular polarization beams.

In the embodiment shown in fig. 9, the high-band control unit includes a pair of first deployment branches 106 "-1 provided on the upper dielectric plate 11, the first deployment branches extending from the radiation loop of the high-band control unit toward the center of the radiation loop 103" -1 of the high-band control unit. The first deployment node is symmetrically disposed on the first diagonal k 1. The low-band control unit includes a pair of second alignment branches 106 "-2 provided on the upper dielectric plate 11, the second alignment branches extending from the radiation loop of the low-band control unit toward the center of the radiation loop 103" -2 of the low-band control unit. The second deployment node is symmetrically disposed on the first diagonal k 1. The first and second deployment branches are configured for fine tuning and optimization of antenna performance.

Although the embodiment shown in fig. 9 includes only one pair of first fitting branches in the high-band control unit and only one pair of second fitting branches in the antenna device according to the second embodiment of the present invention, it is understood that the high-band control unit may include two pairs of first fitting branches disposed on the first and second diagonals, respectively, but having unequal lengths of the branches, and the low-band control unit may include two pairs of second fitting branches disposed on the first and second diagonals, respectively, but having unequal lengths of the branches. The allocation branches are arranged in such a way, so that a perturbation effect can be generated, and the purpose of adjusting and optimizing the frequency is achieved.

The dual-band dual-loop antenna has the working performance shown in fig. 11, and the resonant frequency band can be improved by fine tuning the allocation branches extending from the two radiation loops, so as to meet the impedance bandwidth requirement of the dual-band GNSS.

In the antenna device 1' according to the second embodiment of the present invention, the loop planar antenna architecture is beneficial to independently developing the dual-frequency double-fed circularly polarized GNSS satellite positioning antenna, and the integrated dual-frequency planar design is beneficial to the high-precision satellite positioning requirement of consistent phase center, and the ultra-low profile structure can be flexibly integrated into the vehicle body planar design, so as to facilitate the development of the vehicle-mounted hidden satellite positioning antenna system. In addition, the fringe electric fields of the two working frequency bands have internal constraint characteristics, so that the coupling between the two frequency band radiation loops is reduced, the independent working characteristics between the two frequency bands are facilitated, the outward coupling is restrained, and the influence caused by the external environment is reduced.

Multi-frequency antenna device according to the invention

A multi-frequency antenna device (not shown) having more (i.e., three or more) frequency band control units can be extended based on the single-frequency antenna device according to the first embodiment of the present invention and/or the dual-frequency antenna device according to the second embodiment of the present invention. In the multi-frequency antenna device, the radiation loops of the frequency band control units are arranged on the upper dielectric plate in the same plane and concentrically, the two adjacent radiation loops are separated by a preset distance, the radiation loops of all the frequency band control units are similar in shape, and the symmetry axes are coincident.

Although the parasitic branches and the radiating loops are disposed on the same plane in the embodiment of the present invention shown in fig. 1 and 9, it is understood that the radiating loops and the corresponding parasitic branches in the same frequency band control unit may be disposed on different layers of the upper dielectric plate. For example, the radiating loops in the high-band control unit are disposed on the upper layer of the upper dielectric plate, while the corresponding parasitic branches or parasitic branch loops are disposed on the lower layer of the upper dielectric plate. Alternatively, the radiation loop in the high-band control unit is disposed at a lower layer of the upper dielectric plate, and the corresponding parasitic dendrite or parasitic dendrite ring is disposed at an upper layer of the upper dielectric plate. Also, the radiating loops and corresponding parasitic branches in the low-band control unit may be disposed on different layers of the upper dielectric plate. Advantageously, the radiating loops in the high-band control unit and the radiating loops in the low-band control unit are arranged on the upper dielectric plate in the same plane to ensure that consistency of the phase center for high-precision satellite positioning is always obtained.

The multi-frequency antenna device has the characteristics of ultralow section and a small-size annular plane antenna structure, can be flexibly integrated into the plane design of a vehicle body, and is suitable for a vehicle-mounted hidden antenna of a high-precision GNSS satellite positioning system. In addition, under the condition that the work of the current radiation loop is not influenced, the radiation loops for different GNSS frequency bands and matched short circuit parasitic branches can be conveniently increased, a multi-frequency-band multi-feed antenna structure is obtained, the frequency band application range of the antenna device is expanded, control parts of the multiple frequency bands are integrated on the same pair of dielectric plates, and the compactness and the integration characteristic of the antenna device are further improved. In addition, the radiation loops of all the frequency band control units are positioned on the same plane, the centers of the radiation loops are consistent, no distance difference exists in the height direction, and the consistency of the phase centers for high-precision satellite positioning is ensured. In addition, the radiation loops of each frequency band and the corresponding short circuit parasitic branches form a unique internal beam field design, which is beneficial to improving the influence of the external environment on the antenna system between the control parts of each frequency band.

While the radiating loops of the above-described single-frequency antenna device, dual-frequency antenna device and multi-frequency antenna device are all shown as having a square structure, it is understood that radiating loops of rotationally symmetrical geometry other than square may be used with antenna devices according to the present invention as well. For example, circular, oval, triangular, pentagonal, hexagonal, etc. Correspondingly, the parasitic branches on the parasitic ring adjacent to the radiation loop, which belong to the same frequency band control unit, are tightly coupled with the radiation loop, and the annular fringe electric field can be restrained inwards, so that the coupling with the external environment is reduced. In addition, in each frequency band control unit, the first feed-in point and the second feed-in point are arranged on the corresponding radiation loop in a mode that a specific pole-zero electric field distribution mode is formed. The pole-zero electric field distribution mode is combined with a coupling feed mode, so that coupling between feed ports is greatly reduced. The whole annular radiation structure has symmetrical characteristic, ensures two orthogonal polarization components with equal amplitude, and is convenient for generating circular polarization beams (such as circular polarization satellite positioning beams).

The antenna device 1' according to the invention is advantageously realized on the basis of PCB board processing. The upper layer PCB is supported on the lower layer PCB through a supporting structure. The support structure may comprise parasitic metal posts 104' c, 104' c-1, 104' c-2 for connecting the parasitic branches 104' p, 104' p-1, 104' p-2 of the band control units 10', 10' 1, 10' 2 with the ground plane 12b of the underlying PCB board. The manufacturing process of the antenna device according to the invention is thereby simple and the manufacturing costs are further reduced.

In summary, the antenna device according to the present invention can achieve at least one of the following advantages:

structural characteristics: the planar integrated single-band/double-band/multi-band antenna has a hidden low-profile antenna structure, and is small in size and compact in structure;

electrical characteristics: the 3dBIC circular polarization radiation gain enhances the satellite positioning system quality, the unique electric field zero pole distribution and the unique coupling feed mode form the high isolation of the double feed port, the flexible multi-port multi-band independent design development and the expansion of the communication frequency band, and in addition, the high consistency of the phase center ensures that the high-precision GNSS satellite positioning requirement is met for a double-band or multi-band antenna architecture; and

Engineering characteristics: the manufacturing cost is low, the manufacturing process is simple, the coupling internal field is not easily influenced by the external assembly environment, and the mass production is convenient.

In this context, the azimuth words "upper", "lower", "top" and "bottom" refer to the azimuth that the antenna device is placed in the posture shown in fig. 1. These orientation terms are introduced to facilitate the description of the structure of the antenna device and do not constitute any substantial limitation thereof.

In this context, "high" and "low" in the "high band control unit" and "low band control unit" refer to a comparison of the respective applicable frequencies with respect to each other, the size of the range in which a particular band is located corresponding to the size of the corresponding radiating loop. Here, the applicable frequencies of the high-band control unit and the low-band control unit are not limited to be within a certain range.

It will be appreciated by a person skilled in the art that the individual steps of the method according to the invention are not limited to being carried out in the order listed above. Furthermore, in the present invention, terms such as "comprising" and "including" mean that, in addition to having steps directly and specifically recited in the description and claims, the technical solution of the present application does not exclude the case of having other steps not directly or specifically recited.

While the invention has been described in terms of preferred embodiments, the invention is not limited thereto. Any person skilled in the art shall not depart from the spirit and scope of the present invention and shall accordingly fall within the scope of the invention as defined by the appended claims.

Claims

1. An antenna device is characterized by comprising an upper dielectric plate (11) and a lower dielectric plate (12) which are vertically stacked and arranged at intervals, wherein a grounding layer (12 b) is arranged on the lower dielectric plate (12),

the antenna device (1 ') comprises a frequency band control unit (10 ') comprising a first feed line (101 ') and a second feed line (102 ') arranged on the lower dielectric plate (12) and a radiation loop (103 ') with rotationally symmetrical geometry arranged on the upper dielectric plate (11),

the first feed line (101 ') and the second feed line (102') are coupled to a first feed point (F1) and a second feed point (F2) of the radiation loop (103 ') by means of a first feed structure (1011') and a second feed structure (1021 '), respectively, for feeding the radiation loop (103'), the connection line of the centers of the first feed point and the radiation loop being perpendicular to the connection line of the centers of the second feed point and the radiation loop,

The first feed structure (1011 ') includes a coupling metal post (M1) connected to the first feed line (101') and a patch (P1) located above the coupling metal post (M1) and spaced apart from the radiation loop (103 ') in a vertical direction, the second feed structure (1021') includes a coupling metal post (M2) connected to the second feed line (102 ') and a patch (P2) located above the coupling metal post (M2) and spaced apart from the radiation loop (103') in a vertical direction,

the band control unit (10 ') further includes a plurality of sets of parasitic branches (104 ' p) disposed on the upper dielectric plate (11), each set of parasitic branches being shorted to the ground layer (12 b), the plurality of sets of parasitic branches (104 ' p) being distributed at intervals from each other on an imaginary parasitic ring (C) extending along and adjacent to the radiation loop around a vertical axis passing through a center of the radiation loop (103 '), such that the radiation loop and the parasitic branches combine to form a tightly coupled electric field, the plurality of sets of parasitic branches (104 ' p) being located inside or outside the radiation loop (103 '), the plurality of sets of parasitic branches (104 ' p) including four sets of parasitic branches disposed at positions adjacent to four corners of the radiation loop, respectively, each set of parasitic branches including branch legs (104 ' p1, 104' p 2) extending parallel to adjacent two sides of the radiation loop, the two branch legs (104 ' p1, p 2) being connected to the ground layer (12) via a connecting point of the parasitic pole (104 ' 12),

The antenna device (1 ') comprises two frequency band control units, wherein the radiation loop (103 ' ' -1) of the first frequency band control unit (10 ' ' -1) and the radiation loop (103 ' ' -2) of the second frequency band control unit (10 ' ' -2) are concentric and are arranged on the upper medium plate (11) in the same plane, the radiation loop of the first frequency band control unit and the radiation loop of the second frequency band control unit are similar in shape, the symmetry axes are overlapped, and the two are separated by a preset distance,

the applicable frequency of the first frequency band control unit is higher than that of the second frequency band control unit, the virtual parasitic ring (C-1) of the first frequency band control unit and the radiation loop (103 '-1) of the first frequency band control unit are arranged on the same plane and are positioned at the inner side of the radiation loop (103' -1) of the first frequency band control unit, the virtual parasitic ring (C-2) of the second frequency band control unit and the radiation loop (103 '-2) of the second frequency band control unit are arranged on the same plane and are positioned at the outer side of the radiation loop (103' -2) of the second frequency band control unit,

the radiating loops of the first frequency band control unit and the radiating loops of the second frequency band control unit are square, the two radiating loops have two common diagonals (k 1, k 2), a first feed point (F1-1) and a second feed point (F2-1) of the radiating loops (103 '' -1) of the first frequency band control unit are symmetrically arranged at the center points of two adjacent sides of the radiating loops of the first frequency band control unit with respect to the first diagonal (k 1), respectively, the first feed point (F1-2) and the second feed point (F2-2) of the radiating loops (103 '' -2) of the second frequency band control unit are symmetrically arranged at the center points of two adjacent sides of the radiating loops of the second frequency band control unit with respect to the first diagonal (k 1), and the first feed point (F1-1) and the second feed point (F2-1) of the radiating loops (103 '' -1) of the first frequency band control unit are not located at the center points of the two adjacent sides of the first diagonal (F2) of the radiating loops (103 '' -2) of the second frequency band control unit with respect to the first diagonal (k 2).

2. An antenna arrangement according to claim 1, characterized in that the parasitic branches (104 "p-1) of the first band control element comprise four sets of first parasitic branches arranged on parasitic loops located inside the radiating loop of the first band control element, respectively, adjacent to the four corners of the radiating loop of the first band control element, each set of first parasitic branches comprising branch legs (104" p1-1, 104 "p 2-1) extending parallel to the adjacent two sides of the radiating loop.

3. An antenna arrangement according to claim 1, characterized in that the parasitic branches (104 "p-2) of the second band control element comprise four sets of second parasitic branches arranged on parasitic loops outside the radiating loop of the second band control element, respectively, adjacent to the four corners of the radiating loop of the second band control element, each set of second parasitic branches comprising branch legs (104" p1-2, 104 "p 2-2) extending parallel to the adjacent two sides of the radiating loop.

4. The antenna arrangement according to claim 1, characterized in that the first band control unit comprises a first deployment branch (106 "-1) arranged on the upper dielectric plate (11) extending from the radiating loop (103" -1) of the first band control unit towards the centre of the radiating loop of the first band control unit, at least one pair of symmetrically arranged on the diagonal, and/or that the second band control unit comprises a second deployment branch (106 "-2) arranged on the upper dielectric plate (11) extending from the radiating loop (103" -2) of the second band control unit towards the centre of the radiating loop of the second band control unit, at least pair of symmetrically arranged on the diagonal.

5. The antenna device according to claim 1, wherein the antenna device comprises three or more of the frequency band control units, the radiation loops of the frequency band control units are arranged on the upper dielectric plate in a coplanar and concentric manner, two adjacent radiation loops are separated by a predetermined distance, the radiation loops of all the frequency band control units are similar in shape and the symmetry axes are coincident.

6. An antenna arrangement according to any one of claims 1-5, characterized in that the upper dielectric plate (11) is supported on the lower dielectric plate (12) by means of at least one support structure.

7. The antenna arrangement according to claim 6, characterized in that the at least one supporting structure comprises metal posts (104 'c, 104 "c-1, 104" c-2) for connecting the parasitic branches (104' p, 104 "p-1, 104" p-2) of the frequency band control unit with the ground layer (12 b) of the lower dielectric plate.

8. An antenna device according to any of claims 1-5, characterized in that a hollowed-out structure (13) is formed in the centre of the upper dielectric plate (11).

9. The antenna device according to any of claims 1-5, characterized in that the upper dielectric plate (11) and the lower dielectric plate (12) are PCB boards.